Armored cable connector



R. P. M DONALD 2,265,179

I ARMORED CABLE CONNECTOR Filed May 17, 1939 Patented Dec. 9, 1941 UNITED STATES PATENT OFFICE AR-MORED CABLE CONN ECTOR.

. Robert P.'- MacDonald, Huntington, -N. .Y.

Application May 17, 1939, Serial No. 274,289

11 Claims.

This invention relates to connectors for securing armored cables to wiring boxes and more particularly for securing an armored service entrance cable to a meter or switch box.

It has been found that, with the use of connectors of the type now commonlyemployed, in which the cable clamping .means is on the outside of the box, it is possible, by loosening this clamping means, to slip the armor back far enough to expose the conductors. and to tap such conductors and illegally take. currenttherefrom.

One object of the presentinvention is to providea tamper-proof connector, or,in other words to so construct andarrange a connector .that it will be impossible to mechanically disconnect the i cable from the box or to, slip the armor back-so as to expose the conductors. To this end, I

propose to place the cable clamp on the inside .of

devices, the-invention consists in the construc- 1 tion and arrangement of parts hereinafter described and claimed and illustratedin the accompanying drawing, forming part of this specification, and in which:

Fig. 1 is a front elevation of my improved connector as it appears when applied-to a box;

Fig. 2 is a transverse section on the line 22 thereof, looking in the direction of the arrows, the armored cable itself being shown in dotted lines;

Fig. 3 is a rear elevation of the connector shown in Figs. 1 and 2, looking from the inside of the box; and

Fig. 4 is a perspective view of the connector itself.

Referring to the drawing in detail, my improved connector comprises a body member I havingat one side a semi-circular outline as shown iniFig. 1, and provided with a concentricsocket or opening 2 to receive the armored cable, indicated at A in Fig.2.

Extending rearwardly from the body member I and preferably formed integral therewith is a barrel or elongated socket member 3, terminatpreferably having rounded outer edges, as shown in Fig. 2.

The body I is provided with a laterally'extending flange forming a rigid shoulder or fiat face l adapted to rest against the outside of the box around the hole or opening cut therein to receive the socket member 3, and adjacent the flat face l I provide an enlargement 5 integral with the walls of the socket member 3 and threaded to receive the usual locking nut 6 for securing the connector in place. In installing the connector, the wall of the box B is gripped between the fiat face I and the nut 6, as clearly shown in Fig. 2. 1

Formed integral with the walls of the socket member 3 at .a point between the end 4 and the enlarged threaded portion 5, is a pinch-type clamp comprising resilient tongues conforming with the shape of the socket member 3 and provideda-t their free. ends with upstanding ears 7 adapted to receive a binding screw. 8, in a well known manner.

,In order to provide an independent grounding or bonding means, Iiorm my improved connector with a lateral extension 9, and place adjacent the end of this extension and preferably integral therewith, an inwardly extending threaded stud [0, shown as provided with a pointed-end I0.

In installing my improved connector, 9. hole or opening is first'cut in the box at the desired point, this opening being large enough to receive .the enlarged portion 5 of the connector socket. The socket is then inserted through the opening. and the connector rotated around the socket as a center, thus causing the pointed end HJ of the stud H] to scratch an arcuate line or mark. non the outer wall of the box, as indicated in brokenlines in Fig. 1. The installer thenrernoves the connector and drills a hole at any desired point on the line :t'of a suitable size to receive thestud [0. Having drilled this hole, he may then place the connector in position, as shown in Fig. 2, and secure it in such position by meansof the nut 6 engaging the threaded portion 5 of the socket, and also by means of one ormorenuts ll, engaging the threaded stud Ill, and servingto tightly bond this stud to the box.

Employing this method .of locating the hole'for the :stud- ID, I am enabled to. avoid the necessity of a template.

It will, of course, be understood that the opening in the nut is of such size as to enable it to ing at its end in an inturned annular flange 4, 65 be slipped over the ears 1 of the clamp. It is for this reason that the threaded portion 5 is enlarged, as shown.

The armored cable A is then inserted into the socket of the connector until its end engages the inturned flange or shoulder 4, this acting as a stop to properly position the cable. The conductors C of the cable project into the box through the center of the annular flange 4, the rounded edges of this flange serving to prevent the conductors from being cut or injured.

From the foregoing, it will thus be seen that I have provided an improved connector in which both the locking nut and the cable clamp are lo-. cated inside of the box so as to be inaccessible to unauthorized persons, and that when the cable has once been inserted in the connector and the binding screw 8 tightened up, it will be impossible to disconnect or withdraw the cable or armor.

Preferably the entire connector, asshown in Fig. 4, is formed of an integral casting, the only additional parts required being the nuts and screw. The invention, however, is not necessarily limited to all parts being formed integral, as the stud I0 may be formed separately, if de sired.

What I claim is:

,1. A tamper-proof fitting for connecting armored cables to wiring boxes comprising a member having an elongated socket to receive the cable and also having a rigid shoulder surrounding said socket, a pinch-type clamp formed integral with the'walls of said socket, screw threads on said member between said shoulder and clamp and a nut engaging said threads to grip the wall of the box between said shoulder and said nut.

2. A fitting for connecting armored cables to Wiring boxes comprising a member having an elongated socket to receive the cable and also having a shoulder surrounding said socket, a pinch-type clamp formed integral with the walls of said socket, the walls of said socket between said shoulder and clamp having an enlarged portion, and screw threads formed on said enlarged portion and adapted to receive a nut to grip the wall of the box between itself and said shoulder, said nut being of a size to pass freely over said clamp.

3. A fitting for connecting armored cables to wiring boxes comprising a member having an elongated socket to receive the cable, means adjacent one end of said socket for securing said member to the wall of the box, an inturned flange at the other end of said socket to engage the end of the armor of the cable, and a pinch-type clamp formed integral with the walls of said socket at a point intermediate its ends.

4. A tamper-proof fitting for connecting armored cables to wiring boxes comprising a member having a fiat face adapted to lieagainst the wall of a box and an elongated socket projecting from said face and constructed to receive the cable, means for securing said member in position on a box, and a pinch-type clamp formed integral with the walls of said socket at a point intermediate its ends.

5. A fitting for connecting armored cables to wiring boxes comprising a member having a cable receiving socket formed integral therewith, a nut surrounding said socket for securing said member to a box, said member having a lateral extension, and screw means adjacent the end of said extension and in addition to said nut for bonding said member to the box.

.. an opening, of a tamper-proof connector comprising a member having a laterally extending 'fiange forming .a rigid shoulder engaging the outside of the box and also having a socket adapted to receive an armored cable and extending through said opening into the box, means located inside of the box for clamping the cable in said socket, and a lock nut encircling said socket at a point between said shoulder and clamping means and also, located inside of the box co-operating with said'shoulder for securing said member to the box. 7

8. The combination with a wiring box, of a tampenproof connector comprising a member having a laterally extending flange forming a rigid shoulder engaging the outside of the box and also having a socket adapted to receive an armored cable and extending inside of the box, a pinchtype clamp carried by said socket inside of the box for holding the cable in said socket, and a locking nut encircling said socket between said shoulder and clamp and adapted to engage the inner wall of thebox, said nut being of such size as to slip freely oversaid clamp.

9. The combination with a wiring box having two openings, spaced apart, of a connector comprising a member having a flat face engaging the outside of said box and overlying both said openings, said member having a cable receiving socket extending through one of said openings into the box, means adjacent said opening for securing said member in position, means inside of the box for clamping a cable in said socket, and screw means, in addition to said-securing means, passing through the other of said openings to bond the connector to the box.

10. The combination with a wiring box having an opening, of a tamper-proof connector comprising a member having a socket adapted to receive'an armored'cable and also having a radially extending flange forming a rigid shoulder surrounding said socket, cable clamping means carried by said socket and insertable therewith through said opening into the box, and means located inside the box between said clamping means and shoulder and co-operating with said shoulder for securing said member to theibox.

11. The combination with a wiring box having an opening, of a tamper-proof connector comprising a member having .a-socket adapted to receive an armored cable and also having a rigid shoulder surrounding said socket, cable clamping'means carried by said socket and insertable therewith through said opening into the box until said shoulder engages the outside of the box, and a lock nut, of such size as to slip freely over said clamping means, encircling said socket within the box and engaging the inside of the box, so as to grip the wall of the box between itself and said shoulder and thus secure the member in position.

ROBERT P. MACDONAID. 

